Heart rate increase and inappropriate sinus tachycardia after cryoballoon pulmonary vein isolation for atrial fibrillation.

BACKGROUND: Cryoballoon pulmonary vein isolation (PVI) is a common therapy for atrial fibrillation (AF). While moderately increased sinus rhythm heart rate (HR) after PVI has been observed, inappropriate sinus tachycardia (IST) is a rare phenomenon. We aimed to investigate the prevalence and natural history of an abnormal sinus HR response after cryoballoon PVI. METHODS: We included 169/646 (26.2%) patients with AF undergoing PVI with available Holter recordings before and 3, 6 and 12 months after the procedure. Patients with AF on Holter monitoring were excluded. Mean HR increase ≥ 20 bpm or an IST-like pattern (mean HR > 90 bpm or > 80 bpm when beta-blocking agents were used) following PVI was categorised as abnormal sinus HR response. RESULTS: Following PVI, mean HR ± standard deviation increased in the entire group from 63.5 ± 8.4 to 69.1 ± 9.9 bpm at 3 months (p < 0.001), and to 71.9 ± 9.4 bpm at 6 months (p < 0.001). At 12 months, mean HR was 71.2 ± 10.1 bpm (p < 0.001). Only 7/169 patients (4.1%) met criteria for abnormal sinus HR response: mean HR was 61.9 ± 10.6 bpm (pre-ablation), 84.6 ± 9.8 bpm (3 months), 80.1 ± 6.5 bpm (6 months) and 76.3 ± 10.1 bpm (12 months). Even at 12 months, mean HR was significantly different from that pre-ablation in this group (p = 0.033). However, in patients meeting IST-like pattern criteria, mean HR at 12 months was no longer significantly different from that pre-ablation. CONCLUSION: Few patients had an abnormal sinus HR response after PVI. Peak HR was observed 3 months after PVI, but HR was still significantly increased 12 months post-ablation compared with pre-ablation. An IST-like pattern was rarely observed. In these patients, HR decreased to pre-ablation values within a year.

Rationale and design of the PHOspholamban RElated CArdiomyopathy intervention STudy (i-PHORECAST).

BACKGROUND: The p.Arg14del (c.40_42delAGA) phospholamban (PLN) pathogenic variant is a founder mutation that causes dilated cardiomyopathy (DCM) and arrhythmogenic cardiomyopathy (ACM). Carriers are at increased risk of malignant ventricular arrhythmias and heart failure, which has been ascribed to cardiac fibrosis. Importantly, cardiac fibrosis appears to be an early feature of the disease, occurring in many presymptomatic carriers before the onset of overt disease. As with most monogenic cardiomyopathies, no evidence-based treatment is available for presymptomatic carriers. AIMS: The PHOspholamban RElated CArdiomyopathy intervention STudy (iPHORECAST) is designed to demonstrate that pre-emptive treatment of presymptomatic PLN p.Arg14del carriers using eplerenone, a mineralocorticoid receptor antagonist with established antifibrotic effects, can reduce disease progression and postpone the onset of overt disease. METHODS: iPHORECAST has a multicentre, prospective, randomised, open-label, blinded endpoint (PROBE) design. Presymptomatic PLN p.Arg14del carriers are randomised to receive either 50 mg eplerenone once daily or no treatment. The primary endpoint of the study is a multiparametric assessment of disease progression including cardiac magnetic resonance parameters (left and right ventricular volumes, systolic function and fibrosis), electrocardiographic parameters (QRS voltage, ventricular ectopy), signs and/or symptoms related to DCM and ACM, and cardiovascular death. The follow-up duration is set at 3 years. BASELINE RESULTS: A total of 84 presymptomatic PLN p.Arg14del carriers (n = 42 per group) were included. By design, at baseline, all participants were in New York Heart Association (NHYA) class I and had a left ventricular ejection fraction > 45% and < 2500 ventricular premature contractions during 24-hour Holter monitoring. There were no statistically significant differences between the two groups in any of the baseline characteristics. The study is currently well underway, with the last participants expected to finish in 2021. CONCLUSION: iPHORECAST is a multicentre, prospective randomised controlled trial designed to address whether pre-emptive treatment of PLN p.Arg14del carriers with eplerenone can prevent or delay the onset of cardiomyopathy. iPHORECAST has been registered in the clinicaltrials.gov-register (number: NCT01857856).

Detection of genomic deletions of PKP2 in arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin-2 (PKP2) identified with microarray analysis and/or multiplex ligation-dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis.

Recurrent and founder mutations in the Netherlands : Plakophilin-2 p.Arg79X mutation causing arrhythmogenic right ventricular cardiomyopathy/dysplasia.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited cardiac disease with reduced penetrance and a highly variable expression. Mutations in the gene encoding the plakophilin-2 gene (PKP2) are detected in about 50% of ARVC/D patients. The p.Arg79X mutation in PKP2 has been identified in Europe and North America and has been functionally characterised. We evaluated the prevalence of the p.Arg79X mutation in PKP2 in the Dutch population. METHODS: Twelve index patients and 41 family members were evaluated in three university hospitals in the Netherlands. The diagnosis of ARVC/D was established according to the recently revised Task Force Criteria. Segregation of the p.Arg79X mutation was studied and haplotypes were reconstructed to determine whether the p.Arg79X mutation was a recurrent or a founder mutation. RESULTS: The p.Arg79X mutation in PKP2 was identified in 12 index patients. Haplotype analysis revealed a shared haplotype among Dutch p.Arg79X mutation carriers, indicating a common founder. Six index patients (50%) had a first- or second-degree relative who had died of sudden cardiac death below 40 years of age. At age 60, only 60% of the mutation carriers had experienced any symptoms. There was no significant difference in symptom-free survival and event-free survival between men and women. CONCLUSION: We have identified the largest series of patients with the same desmosome gene mutation in ARVC/D reported to date. This p.Arg79X mutation in PKP2 is a founder mutation in the Dutch population. The phenotypes of PKP2 p.Arg79X mutation carriers illustrate the clinical variability and reduced penetrance often seen in ARVC/D. (Neth Heart J 2010;18:583-91.).

Pulmonary vein isolation of symptomatic refractory paroxysmal and persistent atrial fibrillation: A single centre and single operator experience in the Netherlands.

Aim. To investigate long-term outcome and to determine predictors of successful pulmonary vein isolation (PVI) in patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) who are refractory or intolerant to antiarrhythmic drugs.Background. The treatment of AF has traditionally been pharmacological aimed at rate or rhythm control. However, rhythm control remains difficult to establish. PVI is reported to be effective in selected patient groups.Methods. Ninety-nine consecutive patients with a mean age of 54+/-10 years who had paroxysmal or persistent AF were treated in the University Medical Center Groningen. All patients underwent PVI by the same electrophysiologist. Successful PVI was defined as absence of AF on Holter or electrocardiogram (ECG), and no symptoms of AF.Results. After six months of follow-up, 60 (61%) patients were free of AF episodes, both on 96-hour Holter monitoring and on ECGs, and had no symptoms related to AF. Thirty-nine of these 60 patients (65%) were no longer treated with any class I or III antiarrhythmic drugs. Independent determinants of successful PVI were paroxysmal AF (OR 18 [3.5-93], p=0.001), and left pulmonary vein ablation time >55 minutes (OR 15 [2.7-81], p=0.002). Left atrial (parasternal view 42+/-6 vs. 40+/-5 mm, p<0.05 and apical view 61+/-9 vs. 58+/-8 mm, p<0.05) and right atrial (59+/-7 vs. 56+/-5 mm, p<0.05) sizes decreased significantly in the successfully treated patients after six months of follow-up.Conclusion. Independent determinants of a successful outcome after PVI are paroxysmal AF and a longer left atrial ablation time. (Neth Heart J 2009;17:366-72.).

Phlebotomies as a treatment of serious heart failure due to haemochromatosis: a case report.

Haemochromatosis is a disturbance in the iron metabolism leading to excessive accumulation of iron in various organs such as the liver, pancreas, joints, skin, pituitary, testes and heart, with the last mentioned leading to heart failure. In this report we describe a patient with serious heart failure, attributed to homozygosity for C282Y in the haemochromatosis (HFE) gene, in whom repetitive phlebotomies led to normalisation of left ventricular function. (Neth Heart J 2009;17:438-41.).

[Cardiogenetics: the importance of identifying patients with hereditary heart disease]. / Cardiogenetica: het belang van identificatie van patiënten met een genetische hartaandoening.

During the past decade, developments in the field of DNA diagnostics have resulted in the confirmation of the genetic nature of several cardiac diseases. In a cardiogenetics outpatient clinic, a cardiologist and a clinical geneticist together evaluate persons with a (possible) hereditary cardiac disease. It is of utmost importance that patients with hereditary cardiac diseases be recognised and subsequently referred for genetic counselling as several preventive and therapeutic options are available.

[Life-threatening ventricular tachycardia during flecainide treatment for symptomatic atrial fibrillation in a patient with a structural cardiac disorder]. / Levensbedreigende ventrikeltachycardie bij flecainidebehandeling voor symptomatisch boezemfibrilleren bij structureel cardiaal lijden.

A 37-year-old man with symptomatic acute atrial fibrillation and a low-voltage electrocardiogram was treated with flecainide intravenously. Instead of conversion to sinus rhythm, he developed a wide-complex tachycardia suggestive of ventricular tachycardia. The patient recovered following electric cardioversion. First-choice therapy for symptomatic atrial fibrillation of recent onset (duration < 48 hours) is chemical conversion with a class IC antiarrhythmic drug (e.g. flecainide, propafenone). However, in patients with structural heart disorders, these drugs may induce ventricular tachycardia. A low-voltage electrocardiogram is suggestive of left ventricular damage. For these patients, electric cardioversion is a better alternative.

[Arrhythmogenic right-ventricular cardiomyopathy: different manifestations as precursors of sudden death which might be prevented]. / Aritmogene rechterventrikelcardiomyopathie: verschillende uitingen als voorbode van mogelijk te voorkomen plotse hartdood.

Two men aged 47 and 56 and one woman aged 21 presented at our cardiology department with presyncope, heart failure and exercise induced palpitations, respectively. Using the criteria of McKenna et al., a diagnosis of arrhythmogenic right-ventricular cardiomyopathy (ARVC) was made. Following implantation of a defibrillator, one of the men experienced seven appropriate interventions within six months and also developed psychological problems. The other man was problem-free and the woman recovered reasonably well, having only one appropriate intervention from the defibrillator one year after implantation. Indications of ARVC were also found in her mother but not in any other family members. Because ARVC manifests itself in various different ways it is difficult to diagnose. It is important to consider ARVC in patients with exercise-induced palpitations, presyncope, and unexplained cardiomyopathies or arrhythmias, especially if there is a family history of unexpected deaths. ARVC is a potentially life-threatening disease, that may require implantation of a cardioverter defibrillator. Furthermore, since genetics play an important role and ARVC can be asymptomatic, evaluation of close relatives for preclinical symptoms is important.

Radiofrequency ablation of atrial fibrillation.

UNLABELLED: Twenty-five patients (16 males, mean age 46 years) underwent radiofrequency ablation because of either paroxysmal (13 patients) or persistent atrial fibrillation (12 patients). Ablation aimed at earliest activation of spontaneous and catheter-induced repetitive ectopy in left and right atria and appendages, and pulmonary veins. Catheter-induced repetitive ectopy was defined as acute onset of a burst of rapid atrial premature beats on touching the wall, sustained irritability while at the spot and acute termination of rapid activity upon release of the catheter. Post-ablation patients received antiarrhythmic drugs to prevent tachycardias, thereby allowing reversal of atrial remodeling. RESULTS: Lone atrial fibrillation was present in 19 patients, 4 patients had hypertension and 2 patients coronary artery disease with preserved left ventricular function. The median duration of the history of atrial fibrillation was 4 years (range 1-14 years) and the median number of antiarrhythmic drug failures 5 (range 1-6). Ablation was successful, i.e. no recurrences of atrial fibrillation with or without antiarrhythmic drugs in eight patients (32%) during a median follow-up of 28 months (range 18-52). The median number of foci was 3 (range 2-6) and 2 (range 1-7) in the successfully and unsuccessfully treated patients, respectively. Minor complications occurred in three patients. CONCLUSIONS: Radiofrequency ablation of atrial fibrillation aiming at spontaneous and catheter-induced repetitive ectopy is a safe procedure. However, it is only successful in one third of the patients. Further investigations are warranted to identify the ideal patient, as well as to develop better ablation strategies.